Matter as quantum flow improves computer simulations

If one aims to simulate the interaction of light and matter, the calculations are so complex that the radiation can usually only be described in a traditional manner. However, a European team of researchers including representatives from the University of Innsbruck recently presented a method in the scientific journal “PNAS” enabling them to take the quantum nature of light into account.

In the field of solid state physics, the quantum nature of radiation is usually ignored. However, in other subareas of physics such as quantum optics, this could lead to false or imprecise forecasts. In this case the new type of simulation method should provide assistance.

Due to the fact that the number of particles quickly increases the computational work and time involved, it was common practice up until now to describe such systems as charged liquids. “We have now succeeded in expanding this approach by the quantization of the radiation”, explained Michael Ruggenthaler of the Institute for Theoretical Physics at the University of Innsbruck. “We now consider matter to be a type of quantum liquid whose flow properties are influenced by the photons.”

The advantage of the new method is that it is scalable upwards. It should also function in the case of more complex systems with a larger number of particles. In particular, the researchers are focused on the simulation of so-called nanoswitches i.e. individual molecules which change their electrical conductivity under irradiation. According to Ruggenthaler, the new method could also deepen our understanding of photosynthesis or can be used for the further development of photovoltaic systems.